d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;

    cm.setSize();

  }

  // MOUSE EVENTS

  // Return true when the given mouse event happened in a widget

  function eventInWidget(display, e) {

    for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {

      if (!n || n.ignoreEvents || n.parentNode == display.sizer && n != display.mover) return true;

    }

  }

  // Given a mouse event, find the corresponding position. If liberal

  // is false, it checks whether a gutter or scrollbar was clicked,

  // and returns null if it was. forRect is used by rectangular

  // selections, and tries to estimate a character position even for

  // coordinates beyond the right of the text.

  function posFromMouse(cm, e, liberal, forRect) {

    if (!liberal) {

      var target = e_target(e);

      if (target == display.scrollbarH || target == display.scrollbarV ||

          target == display.scrollbarFiller || target == display.gutterFiller) return null;

    }

    var x, y, space = display.lineSpace.getBoundingClientRect();

    // Fails unpredictably on IE[67] when mouse is dragged around quickly.

    try {

      x = e.clientX - space.left; y = e.clientY - space.top;

      if (!x && !y && e.touches && e.touches.length===1) {

        x = e.touches[0].clientX - space.left;

        y = e.touches[0].clientY - space.top;

      }

    } catch (e) { return null; }

    var coords = coordsChar(cm, x, y), line;

    if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {

      var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;

      coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));

    }

    return coords;

  }

  // A mouse down can be a single click, double click, triple click,

  // start of selection drag, start of text drag, new cursor

  // (ctrl-click), rectangle drag (alt-drag), or xwin

  // middle-click-paste. Or it might be a click on something we should

  // not interfere with, such as a scrollbar or widget.

  function onMouseDown(e) {

    if (signalDOMEvent(this, e)) return;

    var cm = this, display = cm.display;

    display.shift = e.shiftKey;

    if (eventInWidget(display, e)) {

      if (!webkit) {

        // Briefly turn off draggability, to allow widgets to do

        // normal dragging things.

        display.scroller.draggable = false;

        setTimeout(function(){display.scroller.draggable = true;}, 100);

      }

      return;

    }

    if (clickInGutter(cm, e)) return;

    var start = posFromMouse(cm, e);

    window.focus();

    switch (e_button(e)) {

    case 1:

      if (start)

        leftButtonDown(cm, e, start);

      else if (e_target(e) == display.scroller)

        e_preventDefault(e);

      break;

    case 2:

      if (webkit) cm.state.lastMiddleDown = +new Date;

      if (start) extendSelection(cm.doc, start);

      setTimeout(bind(focusInput, cm), 20);

      e_preventDefault(e);

      break;

    case 3:

      if (captureRightClick) onContextMenu(cm, e);

      break;

    }

  }